The present invention relates in general to apparata for the singulation of a gasket from a plurality of gaskets and the subsequent insertion of the singulated gasket into a receiving groove which is formed in another structure, such as a plastic or metal pail lid.
More specifically, the present invention relates to the singulation of a synthetic material gasket from a joined plurality wherein adjacent ones of the individual gaskets are initially joined together by a thin web of material. Singulation of a single gasket from the joined plurality is achieved by cutting, tearing, or in some fashion severing the joining or connecting web of material which is positioned between adjacent gaskets in the stack. Once a single gasket is free from the joined plurality or stack of gaskets, it is available to be handled by automated equipment so as to be positioned for insertion into the selected receiving channel or groove in the other structure.
When the receiving groove is part of a metal or plastic pail lid, the pail lid movement is also automated and timed with the gasket separation (i.e., singulation) steps. The selected pail lid, which is one of a plurality of sequentially staged or indexed pail lids, is moved into position as part of the overall insertion mechanism or apparata, according to the present invention. The gasket is moved into position and the insertion of the gasket into the pail lid groove is completed. Thereafter, the pail lid and gasket assembly is moved off line for subsequent processing.
While the use of synthetic gaskets in pail lids and similar structures is well known, the gaskets which are used are typically supplied to the manufacturer as individual gaskets, packaged in bulk. This means that these gaskets are provided to the end user, in the context of the one performing the installation step, in a turned, twisted, and tangled mass, very similar to a box of rubber bands when supplied in bulk. The particular gaskets which are associated with the present invention can range from as small as 1-xc2xd inches in diameter to as large as 68 inches in diameter with virtually any cross sectional diameter in the case of O-ring styles, or with other overall and cross sectional shapes, depending on the application. Suitable materials for these gaskets include a wide range of elastomeric compounds and the gaskets which are ultimately fabricated can be solid or hollow (tubular) in lateral section. Regardless of the size, shape, or material of the gaskets, one common denominator is the turned, twisted, and tangled arrangement of such gaskets when they are supplied in bulk form. As a consequence, this bulk supply requires manual separation of the gasekts in order to prepare each gasket individually for its subsequent insertion into a pail lid. Whether the gaskets are manually loaded one at a time for insertion, or whether the gaskets are loaded or staged in multiple units for use with automated insertion equipment, each gasket must still be manually separated from the bulk supply, untangled, untwisted, and typically laid flat, at least for most of the present-day insertion equipment. This step of manually untangling each gasket and preparing it in a flat and untwisted form for insertion into a pail lid or similar structure is a time consuming, labor intensive step that adds to the finished pail lid cost. The additional time for this step can also have a bearing on the overall cycle time and through put rate for the pail lid and gasket combination.
Considering the current gasket handling procedures as described above, it would be an improvement if the manual, gasket untangling step could be eliminated and the entire process automated. This assumes that it would be possible to prepare singulated gaskets without twist and generally laid out into a circular form for the automated insertion process. Regardless of the singulation method and mechanism, it is important to have a supply of gaskets so that the repetitive cycle of gasket insertion, pail lid after pail lid, will have only minimal down time and infrequent cycle interruptions for the purposes of loading, securing, or staging a new supply of gaskets for the supply of pail lids.
The present invention provides an improvement to the current (typical) gasket insertion procedures by providing an automated mechanism and a unique sequence of steps to singulate each gasket from a plurality and to do so such that each singulated gasket is prepared for insertion into a pail lid, without any tangles and/or twists.
Gaskets of the type described herein are typically initially molded in the form of a generally cylindrical tube or coil with a series of gaskets sequentially stacked with a very thin connecting web of material between adjacent gaskets. This is the most efficient molding method and design, from the perspective of mold design costs and effectiveness, such that any waste is minimized. It is also important to note that the gaskets which are molded in this fashion are each aligned in a substantially flat orientation in a circular shape, at least for the O-ring shaped gaskets, and there are no twists, turns, or tangles between any of the gaskets of the molded stack. The generally circular form of each gasket accounts for the generally cylindrical configuration of the joined stack.
At the present time, the molder of such gaskets simply singulates the gaskets, one from the others, by severing the connecting web of material and then merely tossing each singulated gasket into a bulk container. Since no time is taken nor any care exercised as to how the gaskets are oriented when singulated and placed into the bulk container, this is where the tangling and twisting begins. If the gaskets are then parceled out into smaller lot quantities for individual orders, additional twisting and tangling can occur. While it might be possible for the OEM molder of the gaskets to carefully singulate and arrange each gasket, free of tangles and twists, the finished singulated gaskets would still have to be stacked or stored in some fashion in order to keep each one twist and tangle free. Similar care would have to be taken during shipment and this would inevitably add to the overall unit cost of each gasket. One of the realities of trying to singulate and prepare each gasket in a tangle-free and twist-free form is the type and style of automated equipment the end users might have. To be most effective, the gasket should be supplied in a form ready to use. This is obviously all wasted if the end user has no desire to automate the gasket insertion process. For example, the gaskets might be supplied with other equipment or parts where a tangled form or twist in the gasket is acceptable. Since there would be an added cost to carefully singulate each molded gasket if some, but not all, customers want tangle-free and twist-free gaskets, then the orders would have to be documented and segregated at the time of molding. Otherwise, all of the gaskets would have to be singulated and stocked in the same manner. What is done now is to simply bulk package the singulated gaskets, under the theory that the lower the unit cost the better and thereby let the end user deal with any twist and tangle problems.
The present invention is designed to accept the tubular (coiled) form of the plurality of molded gaskets, still connected together with the thin web of material between adjacent gaskets. This coiled form or stack of gaskets is utilized in the automated singulation equipment and methods of the present invention in the same way or form that it is molded by the OEM supplier. The molder does not have to singulate each gasket from the cylindrical stack which actually could lower the unit cost of each gasket. By allowing the design of the present invention to singulate each gasket in an automated fashion and to be inserted directly into the pail lid following singulation, no gasket twist is introduced by any of the intermediate processing steps. The results of the apparata and methods of the present invention are to fully automate both the gasket singulation step and the gasket insertion step in a novel and unobvious manner.
A gasket singulation apparatus for separating one gasket from a web-connected stack of gaskets according to one embodiment of the present invention comprises a mandrel for receiving the web-connected stack of gaskets, first support means for positioning the web-connected stack of gaskets at a predetermined location relative to the mandrel, separation means for piercing any web material between a selected pair of axially adjacent gaskets, drive means for axially moving the separation means so as to pull one gasket of the selected pair away from the other gasket of the selected pair, and second support means for supporting those gaskets remaining as part of the web-connected stack as the one gasket is separated from the original web-connected stack.
Also included as part of the present invention is a gasket insertion apparatus for inserting a gasket into an annular receiving groove in a pail lid. The gasket insertion apparatus, according to one embodiment of the present invention, comprises a gasket positioning mandrel defining an annular support lip, pail lid positioning means for moving a pail lid into a gasket-insertion position adjacent the annular support lip, wherein the annular receiving groove opens toward the annular support lip and gasket insertion means for engaging a gasket which is to be positioned on the annular support lip, the gasket insertion means including a gasket-contacting portion and two drive mechanisms wherein one drive mechanism is constructed and arranged for moving the gasket-contacting portion radially and the other drive mechanism is constructed and arranged for moving the gasket-contacting portion axially.
Also included as part of the present invention is a gasket singulation method for separating one gasket from a web-connected stack of gaskets, this particular method according to the present invention utilizes the gasket singulation apparatus described herein.
Additionally, the present invention includes a gasket insertion method for inserting a gasket into a generally annular receiving groove of a pail lid, wherein the gasket insertion method, according to the present invention, utilizes the gasket insertion apparatus described herein.
One object of the present invention is to provide an improved gasket singulation apparatus. Another object of the present invention is to provide an improved gasket insertion apparatus. Another object of the present invention is to provide an improved method of gasket singulation. A still further object of the present invention is to provide an improved method of gasket insertion.
Related objects and advantages of the present invention will be apparent from the following description.